Neuroplasmic flow, the movement of organelles and messages within channels of the neuronal cytoplasm, will be studied biochemically, physiologically, and anatomically. Because microtubules may impart motion to the particles by contractile sidearms, the identification and characterization of sidearm protein will be pursued. These studies will begin with preparations of intact purified microtubules which are available in this laboratory, and will use "antibody reagents" for specific anatomic identification of the structure. The arrangement of sidearms on the microtubule will be studied by a computer - assisted microdensitometric analysis of electron micrographs of intact isolated microtubules. Our Nomarski differential interference contrast microscopic technique will be used to correlate new information about microtubule sidearms with neuroplasmic flow in surviving preparations in vitro. By refining a series of conceptual models of neuroplasmic flow we hope to achieve a detailed understanding of the normal phenomenon. Then this information will be applied to studying human diseases such as peripheral neuropathies and senile brain degenerations which probably involve abnormalities of the neuroplasmic flow system.